(1) Field of the Invention
The present invention relates to a simulation apparatus for a system including a motor-driven compressor and a simulation method, and more particularly to a simulation apparatus and a simulation method suitable for evaluating the feasibility of starting the motor-driven compressor system.
(2) Description of the Related Art
For turbo compressor systems handling process gas in petrochemical fields, motor-driven turbo compressors are often selected to downsize the system and to provide expandability and for other reasons. When a new facility is introduced to a plant, or operating conditions of the plant are changed, the system with a motor-driven turbo compressor boots up the compressor until the compressor operates at its rating, which is so called a “startup” operation executed to ensure safe inauguration of the plant. In a plant design phase prior to the actual check operation, every component of the compressor system is designed to have a capacity great enough to avoid startup failure of the compressor system due to a surge, driving torque shortage and so on. For example, a compressor system is constructed so as to calculate the driving torque required to start the compressor and necessary capacity of the driving motor to achieve the rating.
In a case where complicated processes or the like are required, some operators may be trained using a training simulator to understand the operation processes before actual operations. An example of the training simulation is disclosed in JP-A 1998(H10)-333541. The simulator in this publication employs numerical computations to simulate the process operations of a compressor in order to improve simulation accuracy. More specifically, the simulator uses numerical computations to solve simultaneous equations including multiple functions involving process values of gas fed into the compressor and output process values obtained with property values of various kinds of valves installed at an input and output of the compressor as variables, and outputs the output process values of the compressor.
On the other hand, JP-A 2009-47059 discloses a compressor system including a motor-driven compressor provided with an inlet guide vane and anti-surge valve. In order to achieve great facility cost reduction and optimal design, the system sets a startup control line parallel to a surge line and nearer the operation side than an anti-surge control line and operates the compressor along the startup control line during the startup.